The use of organic solvents for organic polymeric resins in the coatings and resins industry presents a number of problems such as fire hazards, toxicity problems and atmospheric pollution. Additionally, being generally derived from petroleum based materials, organic solvents increase the cost of coating compositions; yet generally do not form part of the final film.
Water based coating compositions do not present the above problems nearly to the same degree as organic solvents. Thus there has arisen an increased need for a wider variety of water soluble or water dispersible polymeric organic resins. Water soluble or dispersible polymeric resins can be especially useful in electrodeposition (electrocoating) processes. The incorporation of carboxyl groups into a polymer with subsequent neutralization by an organic or inorganic base is probably the most common way to impart water solubility or dispersibility to the polymer. For example, it is known to copolymerize acrylates with monomers bearing carboxyl groups to provide carboxyl functionality to the acrylic resin and to at least partially neutralize the carboxyl groups with base. However, depending on the intended use, the presence of carboxyl groups and/or carboxylate groups in the polymer may be undesirable.
Applicants' U.S. Pat. No. 4,322,459 discloses novel resins which are the reaction products of mercapto substituted triazoles or tetrazoles.